I have a 1970 Dodge Dart that originally had a 6 cylinder but now has a newly rebuilt late 70s 360 with minor upgrades such as new edelbrock high performance aluminum heads, new edelbrock intake manifold and 4 barrel card, Hooker Headers and moderate comp cam. The motor sounds great but the car has no get up and go. It won't even squeel the tires. I believe the transmission and rear differential are original to the original 6 cylinder. Now I have a friend that has an original 70 Dart Swinger (340) and it will fly. The body and interior are perfect and would like to take it to some local car gatherings but not until the drive-train issues are dealt with. Any Suggestions?
Are you sure the engine runs ok? Put a vacuum gauge on it an see what your vacuum is, if it's around 15" suspect a blocked exaust. Either that or there is something wrong with the trans. Mkae sure your timing/ points if you have them issues are ok. Does this have anytype of electronic ignition?Also try disconnecting vacuum advance on dist and see I it makes a difference
Try setting timing at about 8-10 degrees advance, but watch out for spark knock.